The activists were travelling from Herat to neighbouring Farah province on Tuesday evening when their convoy was stopped by the Taliban.
Taliban militants have kidnapped 27 peace activists from a highway in Afghanistan's western Farah province, local officials and peace activists said on Wednesday.
Massoud Bakhtawar, the deputy governor of Farah, said the activists were travelling with six cars from Herat to neighbouring Farah on Tuesday evening when their convoy was stopped by the Taliban on a main highway and taken to an unknown location.
Bismillah Watandost, a member of the group, said the activists had planned to travel to various parts of Farah to call for peace and a ceasefire between the warring parties in Afghanistan.
The group, People's Peace Movement, was formed to protest violent attacks after a car bomb exploded at a sport stadium in southern Helmand province last year killing 17 civilians and wounding 50 others.
The Taliban insurgents fighting a Western-backed Kabul government now control more territory than at any time since their austere regime was toppled by US-led forces in 2001. A representative for the insurgents was not immediately available to comment.
Since last year, the activists have travelled to various parts of the country, often marching through Taliban-controlled areas to demand peace and a ceasefire between the Taliban and Afghan government.
The Taliban have previously accused the activists of being financed by the Kabul government among others, which the group have denied.
Tens of thousands of Afghan civilians, members of security forces and 2,400 US military personnel have been killed in fighting since 2001.
US officials have increased diplomatic efforts to reach a peace settlement with the Taliban and to withdraw thousands of troops in exchange for security guarantees.